#include <stdio.h>
#include <math.h>
int main()
{
    int a, b, c;
    scanf("%d%d%d", &a, &b, &c);
    if(a + b <= c || b + c <= a || a + c <= b)
    {
        printf("These sides do not correspond to a valid triangle");
        return 0;
    }
    double s = (a + b + c) / 2.0;
    printf("area = %.2lf; perimeter = %d.00", sqrt(s * (s - a) * (s - b) * (s - c)), a + b + c);
    return 0;
}